Issue 10, 2003

Exploiting supramolecular chemistry in metal recovery: novel zwitterionic extractants for nickel(ii) salts

Abstract

Hexadentate tris-salicylaldimine ligands bearing ortho-N-dialkylaminomethyl substituents have been shown to function as ditopic ligands for NiSO4 or NiCl2. The incorporation of the Ni-ion into the N3O33− site templates the pendant alkylammonium groups to allow them to hydrogen bond to the attendant anion(s). Formulation as complexes of the trianionic/tricationic ligand is supported by X-ray structure determinations of solvated forms of the complexes [Ni(L)SO4] and [Ni(L)Cl]Cl, where L = tris-1,1,1-{2-hydroxy-3-(piperidin-1-ylmethyl)-5-tert-butylbenzaldiminomethyl}ethane. The kerosene-soluble ligand, tris-2,2′,2″-{2-hydroxy-3-(di-n-hexylaminomethyl)-5-nonylbenzaldiminomethyl}amine, functions as a good extractant for nickel salts, showing high selectivity for recovery of NiCl2 over NiSO4. This reagent can be stripped and recycled directly using aqueous ammonia or by first displacing the Ni2+ with acid and then neutralising the pendant alkylammonium groups. The acid-stripping is accompanied by hydrolytic degradation of the reagent, but in many other respects this novel class of reagent shows promise in opening up novel flowsheets for nickel recovery, based on transport of the metal salt as opposed to ion-exchange based processes.

Graphical abstract: Exploiting supramolecular chemistry in metal recovery: novel zwitterionic extractants for nickel(ii) salts

Supplementary files

Article information

Article type
Paper
Submitted
07 Jan 2003
Accepted
24 Jan 2003
First published
23 Apr 2003

Dalton Trans., 2003, 1932-1940

Exploiting supramolecular chemistry in metal recovery: novel zwitterionic extractants for nickel(II) salts

N. Akkus, J. C. Campbell, J. Davidson, D. K. Henderson, H. A. Miller, A. Parkin, S. Parsons, P. G. Plieger, R. M. Swart, P. A. Tasker and L. C. West, Dalton Trans., 2003, 1932 DOI: 10.1039/B300176H

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements